Clinical Trials in California

California has 1,246 clinical trials currently recruiting participants, ranking #1 among all states. The most-studied condition is Schizophrenia with 18 active trials.

1,246

Total Trials

1,246

Recruiting

National Rank

Conditions

Trials by Phase

445

Not Applicable

114

Phase 1 / Phase 2

Phase 2 / Phase 3

Early Phase 1

120

Phase 1

231

Phase 2

241

Phase 3

Phase 4

Top Conditions in California

#	Condition	Trials
1	Schizophrenia	18
2	Ulcerative Colitis	16
3	Pancreatic Cancer	15
4	Autism Spectrum Disorder	15
5	Multiple Sclerosis	15
6	Colorectal Cancer	15
7	Amyotrophic Lateral Sclerosis	14
8	Multiple Myeloma	14
9	Ovarian Cancer	14
10	Sickle Cell Disease	13
11	Obesity	13
12	Obsessive-Compulsive Disorder	13
13	Depression	13
14	Myasthenia Gravis	13
15	Lung Cancer	12
16	Esophageal Cancer	12
17	Prostate Cancer	12
18	Bladder Cancer	12
19	Psoriatic Arthritis	11
20	Rheumatoid Arthritis	11

Top Sponsors in California

#	Sponsor	Trials
1	University of California, San Francisco	61
2	Stanford University	39
3	University of California, Los Angeles	33
4	University of California, San Diego	31
5	AstraZeneca	26
6	City of Hope Medical Center	22
7	AbbVie	20
8	Bristol-Myers Squibb	20
9	Pfizer	18
10	Eli Lilly and Company	18
11	University of California, Davis	17
12	University of Southern California	17
13	Hoffmann-La Roche	17
14	Novartis Pharmaceuticals	17
15	Merck Sharp & Dohme LLC	15

Cities With Most Trials in California

#	City	Trials
1	Los Angeles	564
2	San Francisco	295
3	San Diego	181
4	Orange	155
5	Sacramento	145
6	Palo Alto	137
7	La Jolla	121
8	Duarte	92
9	Stanford	80
10	Irvine	73
11	Long Beach	67
12	Newport Beach	56
13	Torrance	45
14	Fullerton	45
15	Beverly Hills	43

Important: This information is for research purposes only. Always talk to your doctor about whether a clinical trial is right for you.

Frequently Asked Questions

California currently has 1,246 clinical trials actively recruiting participants, making it #1 nationally by total trial count.

The most-studied conditions in California are Schizophrenia (18 trials), Ulcerative Colitis (16 trials), Pancreatic Cancer (15 trials).

Browse the conditions listed on this page to find trials recruiting in California. Each condition page shows trial details, eligibility criteria in plain English, and contact information. Always talk to your doctor about whether a trial is right for you.

Sources: ClinicalTrials.gov

Trial counts reflect currently recruiting studies listed on ClinicalTrials.gov with locations in this state.

California Trial Details →All State Statistics →

The this entity category groups every U.S. clinical trials and research registries entity sharing this attribute. The list above is the data; the paragraphs below explain what the grouping means against the broader the NIH ClinicalTrials.gov registry distribution and how to read the relative rankings within the category.

For readers using this category as a starting point, the per-entity detail pages linked from the table above carry the underlying the NIH ClinicalTrials.gov registry data in full. The category-level view is the filter; the per-entity pages are the actual answer.

Source: ClinicalTrials.gov, 2026.